LOCATION AINSWORTH               IA

Established Series
Rev. JHW-JES-TWN
01/2013

AINSWORTH SERIES

The Ainsworth series consists of very deep, moderately well drained soils formed in 100 to 150 centimeters of silty alluvium and the underlying sandy sediments. These soils are on treads and risers on stream terraces. Slope ranges from 0 to 18 percent. Mean annual air temperature is about 11 degrees C. Mean annual precipitation is about 825 millimeters.

TAXONOMIC CLASS: Fine, smectitic, mesic Typic Hapludalfs

TYPICAL PEDON: Ainsworth silt loam, on a convex slope of about 2 1/2 percent, in a cultivated field, at elevation of about 197 meters above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 centimeters; dark grayish brown (10YR 4/2) and brown (10YR 4/3) silt loam, light brownish gray (10YR 6/2) and pale brown (10YR 6/3) dry; weak fine granular structure; weak platy structure in lower 3 centimeters of horizon; friable; slightly acid; abrupt smooth boundary. (15 to 23 centimeters thick)

Bt1--23 to 46 centimeters; dark yellowish brown (10YR 4/4) and brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure; firm; few distinct clay films on faces of peds; many light gray (10YR 7/2) dry silt coats on faces of peds; few dark concretions (iron and manganese oxides); neutral; gradual smooth boundary.

Bt2--46 to 76 centimeters; yellowish brown (10YR 5/4) and brown (10YR 4/3) silty clay loam; moderate medium subangular blocky structure; firm; common clay films on faces of peds; many light gray (10YR 7/2) dry silt coats on faces of peds; few dark concretions (iron and manganese oxides); strongly acid; gradual smooth boundary.

Bt3--76 to 94 centimeters; yellowish brown (10YR 5/4) and brown (10YR 4/3) silty clay loam; weak fine prismatic structure parting to weak fine subangular blocky; friable; few clay films on faces of peds; common light gray (10YR 7/2) dry silt coats on faces of peds; few dark concretions (iron and manganese oxides); strongly acid; gradual smooth boundary. (Combined thickness of the Bt horizon is 60 to 100 centimeters.)

2Bt4--94 to 111 centimeters; yellowish brown (10YR 5/4) and brown (10YR 4/3) loam; weak medium prismatic structure; friable; few clay films on faces of peds; few light gray (10YR 7/2) dry silt coats on faces of peds; few dark concretions (iron and manganese oxides); few medium distinct strong brown (7.5YR 5/6) redoximorphic concentrations; few fine distinct light brownish gray (10YR 6/2) redoximorphic depletions; moderately acid; gradual smooth boundary. (0 to 25 centimeters thick)

2BC--111 to 132 centimeters; yellowish brown (10YR 5/4) fine sandy loam; weak medium prismatic structure; friable; moderately acid; clear wavy boundary. (0 to 25 centimeters thick)

2C1--132 to 153 centimeters; yellowish brown (10YR 5/4) fine sandy loam; single grain; loose; moderately acid; gradual wavy boundary.

2C2--153 to 203 centimeters; strong brown (7.5YR 5/6) and yellowish brown (10YR 5/4) sand; single grain; loose; moderately acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 108C-Illinois and Iowa Deep Loess and Drift, West Central Part; Washington County, Iowa subset; about 2 miles south of Crawfordsville; located about 1,570 feet east and 1,100 feet north of the southwest corner of section 27, T. 74 N., R. 6 W.; USGS Crawfordsville topographic quadrangle; lat. 41 degrees 10 minutes 50 seconds N. and long. 91 degrees 32 minutes 15 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to sandy sediments--100 to 150 centimeters
Depth to carbonates--greater than 180 centimeters
Clay content in the particle-size control section (weighted average)--35 to 38 percent
Sand content in the particle-size control section (weighted average)--less than 5 percent

Ap horizon:
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--silt loam or silty clay loam
Clay content--20 to 30 percent
Sand content--less than 5 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

A horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--2 or 3
Texture--silt loam or silty clay loam
Clay content--20 to 30 percent
Sand content--less than 5 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral
Thickness--0 to 13 centimeters

E horizon (when present):
Hue--10YR
Value--4 to 6
Chroma--2 or 3
Texture--silt loam
Clay content--18 to 25 percent
Sand content--less than 5 percent
Rock fragment content--0 percent
Reaction--strongly acid to slightly acid

Some pedons have a BE horizon as much as 20 centimeters thick

Bt horizon:
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--3 or 4
Texture--silty clay loam
Clay content--35 to 40 percent
Sand content--less than 5 percent
Rock fragment content--0 percent
Reaction--very strongly acid to neutral

2Bt horizon (when present):
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--2 to 4
Texture--loam or clay loam
Clay content--20 to 30 percent
Sand content--15 to 35 percent
Rock fragment content--0 percent
Reaction--very strongly acid to moderately acid

2BC horizon (when present):
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--2 to 4
Texture--sandy loam, loam, or fine sandy loam
Clay content--10 to 18 percent
Sand content--45 to 75 percent
Rock fragment content--0 to 5 percent, mixed lithology
Reaction--very strongly acid to moderately acid

2C horizon:
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--3 to 6
Texture--fine sandy loam, sand, or loamy sand
Clay content--5 to 15 percent
Sand content--70 to 95 percent
Rock fragment content--0 to 5 percent, mixed lithology
Reaction--very strongly acid to moderately acid

COMPETING SERIES: These are the Bonnefemme, Brevator, Clinton, Haymarket, Lunt, Mirerock, and Welda series.
Bonnefemme--have a lithic contact within a depth of 100 centimeters
Brevator--have a clay content of 35 to 50 percent in the lower third of the series control section
Clinton--a sand content of less than 5 percent in the lower third of the series control section
Haymarket--are in areas that have a mean annual precipitation range of 910 to 1,120 millimeters and may contain rock fragments of diabase or basalt
Lunt--are in areas that have a mean annual precipitation range of 960 to 1,120 millimeters and have a rock fragment content, mainly quartz, of 1 to 10 percent in the upper half of the series control section
Mirerock--are in areas that have a mean annual precipitation range of 910 to 1,120 millimeters and have a paralithic contact within a depth of 100 centimeters
Welda--contain less than 20 percent sand in the lower third of the series control section

GEOGRAPHIC SETTING:
Parent material--100 to 150 centimeters of silty alluvium and the underlying sandy sediments
Landform--treads and risers on stream terraces
Slope--0 to 18 percent
Elevation--168 to 213 meters above sea level
Mean annual air temperature--9 to 12 degrees C
Mean annual precipitation--780 to 870 millimeters
Frost-free period--160 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coppock, Koszta, Lawson, and Okaw soils.
Coppock--are at lower landscape positions on flood plains and have an average clay content of 27 to 35 percent in the particle-size control section
Koszta--are at slightly lower landscape positions on stream terraces and have an average clay content of 27 to 35 percent in the particle-size control section
Lawson--are at lower landscape positions on flood plains commonly adjacent to the stream channels and have mollic epipedons that are greater than 60 centimeters thick
Okaw--are at higher landscape positions on nearly level areas on stream terraces and have an average clay content of 40 to 60 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs at a depth of 1 meter during April to June in normal years and is considered apparent
Saturated hydraulic conductivity--1.0 to 10.0 micrometers per second (moderately high) in the silty sediments and 10.0 to 100 micrometers (high) in the underlying sandy sediments
Surface runoff potential--negligible to medium
Flooding--rarely flooded for brief or very brief duration

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. Oats and legume-grass hays are also grown in some areas. A few areas remain in native hardwoods.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Illinois and Iowa Deep Loess and Drift (108) and Iowa and Missouri Heavy Till Plain (109)
LRR M; southern and southeastern Iowa
Extent--small

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Henry County, Iowa, 1982.

REMARKS:
Particle-size control section--the zone from a depth of 23 to 73 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.

Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 23 centimeters (Ap horizon);
argillic horizon--the zone from a depth of 23 to 111 centimeters (Bt1, Bt2, Bt3, and 2Bt4 horizon);
udic moisture regime.

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska - user pedon ID 03IA183001 (http://ssldata.nrcs.usda.gov/).

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National Cooperative Soil Survey
U.S.A.